Crossbar switch



R. P. ARTHUR CROSSBAR SWITCH Sept. 23, 1952 3 Sheets-Sheet 1 Filed Dec. 3, 1949 to nun-nun, 5 illllll INVENTOR: RlCHARD P. ARTHUR BYWVI W7 A ATTORNEY R. P. ARTHUR CROSSBAR SWITCH Sept. 23, 1952 3 Sheets-Sheet 2 Filed Dec. 3, 1949 R. P. ARTHUR CROSSBAR SWITCH Sept. 23, 1952 I5 Sheets-Sheet 3 Filed Dec. 3, 1949 FIG. 4-

INVENTOR'.

R U m m W A R m mm A H m R Patented Sept. 23, 1952 UNI TED STAT FATE OFFICE-S1 GEES-SEAR SWITCH Richard! P.: Arthur; Chicago; a Ill.;.: assi'gnor; .11m mesne' assignments, to Kellogg q Switchboard -and Supply-Company, :a, corporation. of Delaware l Applicatiofi Decembe'r -fi, 1949, Serial No. 131,003

This: inventionfrelates :to a crossbarswitch'sz;:Its principal i'obj'e'cti is to aprovidexa morersatisfac tory and economical construction irofnthexpartsf directly-s involved inJthezselectioncrand r operation of:the desiredxstackup; of .;contact Sets'h-x Addie: 5 tionalaobjects iare'tto simplify: and: 'improvevthe:. construction cwherever tprac-ticablerr. to s facilitate manufacturer: assemblwi and. adjustment: a I

GENERAL DESCRIPTION A crossbar. switch is one having-permanently: paired :icontact 'membersi. comprising --sets;i- (or stackups)v arranged in intersecting"-rows hereee matter .-.respectivelv termed: yerticalarows vrand horizontalirowsa Selectingbars i0! shafts) sex-e tend .1 along; the: horizontal rows to i :select 1 I then-. staokups, therein; Hold :bars (or armatures) exa vv tend-respectively along the vertical rowstoactu-n-v ate, and hold, selectedistackupsa r It hasbeen. chosen-to illustrate-.the-. invention as appliedzto -a crossbarswitch asrdisclosed inthe pending application. rof .Richardt Pm' Arthur-,4: Crossbar-Switch,:Serial No.-8-,900, filed-February 1'],- l948-.: The--:noted. .Arthur applicationwwill hereinafter-be termed the"formerl-applicationior disclosure. r p

The; principal .sfeature of the invention r resides, in an improvedwarrangement of .the parts di-m rectly involved in selecting and operatinga de -l.-

siredstackup of contactmembersveAn outstande mg characteristic of the new-arrangement. is that l the underlying actuatinglmembereori tabiffoix a stacku'p; is rendered .fmnecessary; lands thenassoi-lciated select lever directlyfactuates' the stackuprt In- .the' disclosed embodiment, lthe stackup ine-U left and right framemembers 2 and-"4 suitably" eludes an actuating ladder" which ha'sa widefporr-i tion resting on a backstop bar to determine the normal position of thetstackupm A reduced depending portion of the ladder passes through an opening in'the lbackstopmar'toa level'atz'whmh io s bars or hold-magnet arm'atures ram-renown? it is directly-eng-agedand lifted-by the'associatedselect lever: X

A related featureds thataccurateguiding-moi thestackup' ladder is readily obtainedby properly sizing the: noted opening in the backstop bara tchannelsl. 25% 4 Abrasive action: on theiladder/ is avoided-by, am eyeletitype; of grommet lining the noted opening in: the bacl zstoptbar.--

A further advantage of the noted' improvedear-x rangementis thatthe armature structurerfor EOE-They; upperiflanges;iofigbothimemberervewas actuating any. selectedstackup in the same vertie i; cal rowamay =be readilycproduced in one piece from: sheetzstochw According to a further.:feature;ithesdaterallyi-13- adjustable;endzbearing 'ofitheaiarmaturefinciudes iorilthezhold magnet'afluxs Th expo'sedafaceor partsi'for takingiupwenduplayrwhich man-other. 1:- wise exist at somezof'theiaramtureseof aswitchc e Other-:objectsx.and features of the inventiomi will I appear; :as- :the description progresses; I a

Theschosen embodiment 'of ther inventioniwill; now: be idescribed-rin connectioniwith the: accom panying idrawingsacomprisingc-Figst 1 itovv 4, .-i which? Fig. 1 shows a top.yieweofutheiimproved-crosser Fig; 2 shows a front wiew of the"crossbarrswl'tch with certain parts broken away,-sand otheripartsaa removed 2 Fig- 3 showsafragmentary perspective-viewmf the sta'ckup selecting and operating-mechanismemployed at any vertical row of-stackupspandnz Fig.--4 shows an enlarged i-fragmentary fronter view-,--partly in section, showing thet-stackupgselooting and operating mechanism at tone (of the stackups in the first vertical rows v DETAILEDDESCRIPTIdNiar A detailed description orthe' constructionaandi-i operation of the improved crossbarswitch 'wnr' now be given.

I. CONSTRUCTION Referring"now'partieulamy "to "Figs. "1 and: 2, theswitckcomprisesa 'contacvba'nkproviding: the desired number *and'arrangement of stack '1 lips; together with a rectangular "structurefiof" supporting the contactbank and controlling'the f desired-actuationof the stackups-thereofti'i The? supporting and 1 controlling structure"includes"'zi (1) front and rear framemem-bers "l ands; and:-

secured thereto through corner gussets-E and'*'6', 2) sixhorizontal bars or -select-shafts S'l i to SH -I 2; p'ivotal-ly mounted -between shaft brackets l 8 and l 9, (3) a 'desi-red number ofverticali i mounted between-front and'rear members-l and 3, and (4) a contact bank providingstakups comprising Vertical -rows overlying-the respective armatures 9 0, the "Contact bank being supported- The front'frame 'membe'r' l'is an=uprightmemi-' herewith an inwardly extending-=uppecfiah'g The'f rear memberia is a similanstructurerbiit with an: inwardly extendin'g lower "flange added mounting supports -for cross members 25W1hil'e theix-lowersflangeton rear memberfi serves -as' mountingmsl port iori-hoid mag-nets 86? The T- rearimember;tbeing iron, provides ="areturn-path front member I, as seen in Fig. 2, contains elonated holes III to receive the armature leveling assembly I I2. Rollers I0, attached to the right and left end members 2 and 4, permit the switch to be easily moved forwardly and rearwardly on a suitable track (not shown).

Shaft brackets I8 and I9, extending across the switch frame at the ends, are angle structures with the upper web extending outwardly. They are secured to the rectangular frame by screws passing through corner gussets 5 and 6. The vertical portion of these brackets support the select shafts, SI-2 to SII-I2, while the flanged portion supports the select magnets MI to MI2, together with brackets 204. Brackets I8 and I9 provide magnetic return paths for the selectmagnet flux. I

Cross channels (or support channels) are secured to the upper flanges of front and rear frame members I and 3 by screws 26. Elongated apertures 22I permit channels 25 to be adjustably aligned. The contactstackups are secured tothe support channels by screws I53 entering tapped holes 21, while the hold-pilot assemblies (at the top of Fig. 1) are secured to the support channels by screws I89 entering tapped holes 28. Holes 29 are provided in support channel 25 for holding dowel pins used only in aligning the stackup members during assembly.

Each vertical row of stackups is provided with a backstop bar 225. Bar 225 is a channel structure with upwardly extending flanges, and is secured at each end to support channel 25 by screws 226 which extend through mounting notches 238 in the backstop bar. Each backstop bar 225 contains punched holes through each of which a reduced portion of a stackup ladder 222 is extended toa level at which it may be engaged and lifted by an associated select lever 220 as will hereinafter be described.

By loosening screws 226, backstop bar 225 may be raised or lowered to adjust the normal position'of'stackup ladders 222.

IA. Select magnets and shafts" Six pairs of. select magnets MI and M2, M3 and M4,'etc., and their associated six select shafts, SI -,2, S3-4, etc., are provided for the six pairs of horizontal rows of stackups. The noted select shafts are pivotally mounted to permit their rotation in either direction from normal position to select the corresponding one of the two associated horizontal rows of stackups, depending upon which one of the two associated select magnets is energized.

Each select magnet includes an energizing coil wound on a core 82. To permit external connections the coils of the select magnets are provided with terminals 83 mounted on spoolhead 85. Select magnets MI and M2, M5 and M6, and M9 and MI!) are mounted on shaft bracket I8, while magnets M3 and M4, M1 and M8, and MII and MI2' are mounted on shaft bracket I9. Each select magnet core 82 is drilled and tapped at its mounting end to receive mounting screw 2| I. Collars 209, against which cores 82 are held by screws 2| I, are threaded into tapped holes in the flanged portion of shaft brackets I8 and I9. When rotated, they longitudinally adjust the select magnets to determine the front stop position of armatures 5|. Collars 209 are provided with a hexagonally shaped shoulder to facilitate their rotation. A hexagonally shaped cup-like member 2 t 0 placed over the shoulder of collar 209.

4 looks the structure rigidly in its adjusted position when screw 2| I is tightened.

Th select shafts are pivotally mounted at each end as fully described in the noted former application. Bearing screw 45, with its lock nut 48, serves to adjust against excessive end play.

Each select shaft has an armature 5I (shown in Fig. 2) underlying each of the two associated select magnets. With the shaft pivoted ata point between the select magnets, energization of either magnet attracts the armature in the corresponding direction to rotate the select shaft in the same direction.

As shown in the former application, each select shaft has an off-normal stackup and shaft-restoring member (on brackets 204) associated with the armature end thereof. From the noted locations of magnets MI to MI2, it will be observed that the first, third, and fifth select shafts are mounted with their armatures at the left end of the switch while the second, fourth, and sixth select shafts are mounted with their armatures at theright end of the switch.

Support brackets 204, mounted above their associated select shafts, are secured to the flanged portion'of shaft brackets I8 and I9 by screws 205. The vertical portion of bracket 204 supports the off-normal stackup and shaft restoring member 66.

A shaft restoring member 66 is provided for each select shaft and comprises a flat structure with a V-notched portion arranged to engage shaft positioning rollers '69. Members 66, tensioned against rollers 69 by spring 65 and secured to bracket 204 by off-normal stackup screws 68, position rollers 69 in the V-notched portion. Rollers 69, which are attached to their associated select shafts by studs "I0, maintain the unoperated select shafts in their non-selecting position.

The tension of restoring members 66 against positioning rollers 69 is readily adjustable by bending the vertical portion of brackets 204 toward or away from their associated shaft brackets. Energization of any select magnet will cause the associated select shaft and stud assembly 10;

to rotate. Rotation of stud 10 causes rollers 59 to extend member 66 back against the tensioned spring65 and actuate the offenormal springs I5.

Contacts on these springs may be used for pilot purposes to indicate that a select shaft has been moved into a selecting position.

Deenergization of the select magnet will permit the tension of spring 65 against roller 69 to return stud 10 to its center position. This causes the associated select shaft to be returned to its nonselecting position.

IB. Hold magnets and armatures A hold magnet and associated armature are provided for each vertical row of contact stackups. Hold magnets 80 shown in Fig. 2 are adjustably mounted upon the lower flange of rear frame member 3, below and slightly to the left of their associated stackups. -Armatures 90,

struction as the hereinbefore described select magnets. The hold magnets are mounted and longitudinally adjusted in the same manner. as

the noted select magnets.

Mounting tab 93 of armatureflllisipivotally cured to'therear frame member 3: by bearing cilitates this adjustment and lock nut 201 looks the bearing screw in its adjusted position. Plate assembly screw II3 passes through elongated apertures IiIIIEin plate'I I2 and'threads into tapped holes in the face of front frame member I to adjustably secure plate II2J to the outside of member I. Elongated apertures. I I4 in plate H2 and elongated apertures II I in theface of the front frame member I throughwhich bearing screw 206 passes, permit/plate II2 to be raised or lowered to levelarmature 90. This armaturemounting arrangement serves'toproperly adjust thetclearance' under stackup ladder 222 necessary for the. selecting levers 220 in assuming their alternate: selecting positions. Armature 90 is readily removed by loosening locking nut 201, backing out bearing screw 206, disengaging bearing pin I09 and dropping the armature out of the switch-structure.

Armature90 comprises two principal portions formed integrally with each other; a tractive portion 9I which overlies the upper end of the core oiiits associated hold magnetand a laterally extending (main) portion which underlies the associated rows of contact stackups. Energization of any hold'magnet '80 attracts portion 9| of the associated" armature into engagement with the energized'magnet, causing armature 90 to rotate about its pivots. A residual clip II! is provided, as shown in Fig. 3, and attached'to tractive portion 91 ofarmature 90 to eliminate any undesirable residual magnetism.

As previously noted, the front stop position of thearmature 90 is regulated by-the longitudinal adjustment of the hold magnet. The back stop position of armature 90 is regulated by adjustable backstop screw I I5 (shown in Figs. 2 and 4) which is threaded through the upper flanged portion of rear frame member 3 for engagement with the tractive portion. 9I of armature 90. Backstop screw H5 is locked into its adjusted position by lock nut II6. Restoring spring 223 shown in Figs. 1 and 3, is secured to backstop bar 225 by screw 224 and is tensioned against armature 90 to retain portion 9| in its normal (unoperated) position against backstop screw II5.

Tab-like portion IOI, underlying the associated hold-pilot stackups. serves to actuate the hold- .pilot contact sets when the armature is rotated. Tab IOI is upwardly oifset so that it lies in the same plane as the top of elevated platform 2'" of select lever 220. Armature rotation, there- 'fore, causesthe hold-pilot stackup ladder and the selected stackup ladder to be actuated simultaneously.

The laterally extending portion of armature 90 comprises an integrally formed select-lever mounting plate 2'14 and an elevated plate-like structure 2I2 Select-lever mounting plate 2I4 includes. six holes 2 I5 for receiving shoulder rivets 216 which pivotally secure select levers 220 to armature 90-. Structure 2 I2 includes six recesses 2 I 3-, thesides; of which engage. select+lever downwardly extending tab 2 I9' (seeFig. 4 to 'provide stop positions. for. select'leverss'220'.

16.. Bank. construction The .constructionof the contact bankfsupported on channels 25, to providethe.verticalland horizontal rows of selectively operable. contactmembers is as disclosed in the principal embodiment of the former application. y

The contact bank, disclosed in thisinvention, is the modified bank construction of. the former application wherein the flexible contact, springs are the vertical comb-like conducting strips and the fixed contact members are the. horizontal conducting strips. M

As seen in Figs. 2' and 4, the stackups comprise six contact pairs instead of? the three shown in the modified embodiment of the. former application.

stackup control As shown in Figs. 2 and 4, a stackupactuating ladder 222 is provided for each stackup of contacts contained in the switch structure; "Responding to the rotation of hold-magnetarmature 90, stackup-actuating ladder 222,..bytits'upwardmovement actuates associated contact stackups. Ladder 222, formedfrom an. insulat ing material, comprises generally a flat elongated structure including forwardly extendingstep-like lifting portions 236 and 231, a wide portion or shoulder 234 and a reduced downwardly extending portion 235.

Liftingportions 236 and 231 support the downwardly tensioned traveling, springs of their as sociated stackups. The downward tension of the traveling springs causes shoulder portion234 of ladder 222 to rest on an eyelet type of grommet 22'I placed in punched holes in backstop bar'225. Reduced portion 235 extends through grommet 221 to a level, determined by shoulder 234, which permits select levers 220 to be easily positioned beneath it responsive to their associated'select shaft rotation. Grommet 221 while preventing abrasive action on the sidesand edges of reduced portion 235 also serves as guide holes for the upward and downward movement of ladder 222. The uppermost lifting portion 231 of ladder 222, by an upwardly extending portion, maintainsthe ladder vertically positioned.

Ladders 222 may be removed by loosening screw 226 and lowering backstop bar 225.

Actuation of any stackup of the contact bank is effected by flexing the traveling springs thereof, upwardly into engagement with their associated fixed contact members. For this purpose. each stackup is provided with an actuating ladder 222, hereinbefore described. Ladder 222 extends through an intermediate portion of the flexible traveling springs of its stackups and its step-like lifting portions 236 and 23! engage the traveling springs, lightly tensioned downwardly.

When ladder 222 is elevated, by energization of the associated hold magnet as hereinafterdescribedthe traveling springs are flexed upwardly until their'contact points engage those of the as.- sociated fixed contact members. Further upward movement. (or over-travel) of lad-der 222, after the traveling springs engage the fixed members, causes the traveling spring to bow as theicontact pressure is built up. If the previously described armature-leveling adjustment is accurately made, the contact pressure resulting from the desired slight over travel is the same'for all stackups in a vertical row. The extent of the over-travel-is deter-mined by the hereinbefore-noted longitudinal adjustment of the hold magnet.

When the energized hold magnet is released,

the tension of the traveling springs against the lifting portion of actuating ladder 222 is great enough to return the ladder to its resting position against grommet 221.

The hold-pilot stackups are assumed to be as disclosed in the former application. The holdpilot stackup actuating ladder is of the same general construction as actuating ladder 222, one exception being that the hold-pilot ladder is of a shorter length. Rotation of hold-magnet armature 90 causes upwardly extending tab IOI to elevate the hold-pilot stackup ladder thereby actuating the associated contact sets.

IE. Selecting mechanism In every vertical row of contact stackups, a pair of stackups are associated with each select shaft. A selecting lever 220 is associated with each such pair of contact stackups and when in its normal (unoperated) condition, occupies a position midway between and below the associated pair of stackups. Figs. 2 and 4 represent a front view of levers 220 and show the relationship existing between the levers and sta-ckup ladder 222. A top view of the levers in their normal position are shown in Fig. 1.

Referring particularly to Fig. 3, one such select lever 220 is shown to comprise generally a T-shaped structure lying in a horizontal plane. Select levers 220, formed from sheet metal, and pivotally secured to armature portion 2I4 by shoulder rivet 2I6, has two raised platforms 2H and a downwardly extending tab 2I9 (see Fig. 4). The portion of select lever 220 containing elevated platforms 2!! is raised to a level whereby it rests flatly on raised armature portion 2I2. V When the select lever is positioned beneath the selected stackup by rotation of its associated select shaft provided the hold-magnet armature is in its normal unoperated position, raised platformsZI'I are positioned underlying the associated stackup ladder 222.

The downwardly extending tab 2I9, shown in Figs. 3 and 4, lies within recessed portion 2| 3 (see Fig. l) and is flanged so as to underlie the hold-magnet armature portion 2I2 to prevent any upward movement of the select lever unless accompanied by its associated armature 90. When the select lever is moved in either direction for its selecting action, tab 2| 9 in engaging the sides of recesses 2I3 provide stop positions so that the select levers properly underlies its associated selected stackup.

Each selecting lever is moved from its normal position to its front or rear selecting positions by the positive action of a finger spring I30 acting in response to the select shaft rotation. As viewed from the left end of the switch illustrated in Fig. 1, rotation of the select shafts in a clockwise direction moves the associated select levers 220 to their front-selecting position and counter-clockwise rotation of the shaft moves the select levers to their rear-selecting position. The finger spring I33 as shown in Fig. 3, comprises generally a vertically extending hairpin-shaped member constructed of a single piece of spring material shaped to form a loop I3! at one end and having two vertically extending driving arms I32 terminating in outwardly turned end portion I33.

Arms I32, engaging select lever 20!] at its midportion 2I8, serves as a yielding drive means effective to drive the associated select lever, unless restrained, into one of its three positions (the illustrated position, its front select position,

and its rear select position) in response to the rotationof its selecting shaft in the corresponding direction.

Arms I 32 are driven by neck portion 233 of finger guide 230, against which they are inwardly tensioned. These arms are contained within guide channels 228 and 229. Either finger I32 moves along its guide channel, away from neck portion 233, incidental to its select lever beirlilg restrained from following the rotation oi the s aft.

Loop portion I3I of spring I30 rests upon the top surface of curved finger-guide mounting 232 and is retained in position by tabs 23 I. Accordingly, the matched tension of the driving arms I32 provides for a following action of one arm when the other arm is driven, wherefore both arms act as one long spring.

Finger guide 23 is secured to its associated select shaft by mounting structure 232. Fingerguide mounting 232 is 'a curved structure conforming to the contour of the select shafts and is secured, as by welding, to its associated select shafts.

II. OPERATION IIA. Select magnet operation Selection of the first horizontal row of contact stackups occurs responsive to the energization of select magnet MI (Figs. 1 and 2). The underlying armature portion is attracted upwardly into engagement with the core of select magnet MI causing select shaft SI-2, viewed from its armature end, to rotate in a clockwise direction. Thereupon, select finger guides 230 of shaft Sl-Z, one for each vertical row of stackups, are moved to a position underlying horizontal row I. At each idle vertical row of stackups (hold-magnet armature being in its unoperated position) select-finger guides 230 cause select-finger springs I33 to rotate the associated select lever 220 about its pivot (shoulder rivet 2I6) toward an effective position below the first horizontal row of stackups. The front elevated platform 2I1 of select lever 220, as viewed in Fig. 1, is brought effectively beneath reduced portion 235 of its associated stackup ladder 222 in the first horizontal row. The first stackup is thereby selected in each idle vertical row in the switch.

The completion of the rotation of select shafts preferably occurs just as the downwardly extending tab 2I9 of any select lever 220 is about to strike the side or stop position of recesses 2| 3. The select shafts may be arranged, by the previously described longitudinal adjustment of the select-magnet cores, to rotate through a slightly larger angle than is required for the select'levers 220 to reach the noted stop position. This excess shaft rotation,insuring that all the select levers are rotated a suiiicient amount, is permitted by virtue of the inherent flexibility of the described select finger springs I30. The driving arms I32 merely yield as soon as tab 2I9 engages its stop position in recesses 2I3.

If any vertical row of the switch is in use when the selective action just described occurs, the raised condition of armature 98' causes front raised platform 2i! to strike the sides of its associated stackup ladder 222. This action prevents select levers 220 from reaching their selecting positions but does not interferewith the full stroke of the select shaft as the concerned driving arms I32 merely flex as the select shaft completes its movement- Selection of any horizontal row of contact ackups,-is aeeemplishesi.fxthe .en reizatien. o

Following the previously described selecting action of horizontal row I and while the concerned select magnet MI is maintained energized, the hold magnet 80 associated with any idle vertical row of contact stackup is energized. Tractive portion SI of hold, magnet armature 90 is attracted downwardly into engagement withthe core, of hold magnet 80, rotating armature .90 about its pivotally mounting, arrangement previously described. This rotating action raises portion 2I2 of armature 90 withall its selecting levers 220. Each such lever passes ineffectively between the associated reduced portion 235 of stackup ladder 222, except in the case of the selected first stackup of the vertical row associated with the energized hold magnet 80. Select lever portion 2I1 engages the reduced portion 235 of ladder 222 associated with the noted first stackup and raises ladder 222 causing it to upwardly carry its associated stackup traveling springs.

When the armature stroke is only partially completed, the traveling springs of the noted first stackup engage their associated fixed contact members. The final portion of the movement of the armature 90 causes the traveling springs to bow as contact pressure increases as hereinbefore described. The hold magnet 80 is maintained energized as long as the connection established is to remain intact.

IIC. Select magnet release The energized select magnet, after the operation of the desired hold magnet, may be deenergized immediately. When this occurs, the cam springs 65 and cam member 66 associated with roller stud I attached to the select shaft, return the associated select shaft to its normal unoperated position.

When the selecting shaft used in selecting a particular horizontal row of stackups is returned to its unoperated position, the selecting levers 220 associated with the unoperated hold-magnet armatures are returned to their normal positions, but the lever 220 asosciated with the operated armature 90 is retained in its selecting position by the downward pressure exerted on it by the traveling springs of the actuated stackup. The rear driving arm I32 of the concerned finger spring I30 remains in its selecting position and fiexes as the select shaft is returned to its normal position, while the front driving arm I32 returns with the shaft.

IID. Hold magnet release The energized hold magnet associated with an established connection is deenergized when the connection is released. Armature 90, therefore, rotates back to its normal position by virtue of the downwardly exerted pressure of armaturerestoring spring 223. The tension of the traveling springs in the operated stackup assist in the initial portion of the return movement.

When the armature portion 2 I2 is lowered, the select lever 220 is released from the ladder 222, whereupon the spring action of the rear driving arm I32 of finger spring I30, exerted against the midportion 2; of select lever 220, causes the select lever to realign itself with finger spring I30 of its associated shaft in its normal position as shown in Figs. 1 and 3.

- I aim;

1. Ina ero e erewi h emple ing. stackup of contact members, select levers for respective pai s o sa det p n e ly n common ace tuating plate movable toward the stackups -for tuat n i e o e s bjec to the 3 ,597. ciated select lever having-been interposed be ween h u t g p e a s c st wkup, ach. select lever comprising a single member in the ne a form e n a shee of 1th n;me. r al, ach l v l" havin a is eni gt ere hreuel ato e n a a t n it is bep veted 9n neup-per sidee th -actuat ng late andte r tate se se ii -ei hersd ree enr-ireme .p'es tien. ermediate -therstaeknp .ef its, a sqeiatedrai 9x a positi n. eperati elyl b 936: either, desired .enai said lever including a tab extending downwardly from and then parallel to the main portion of the lever to provide opposed surfaces for guiding the movement thereof, said plate being slotted below the downwardly extending portion of any tab to receive such portion, the said parallelly extending portion of any tab extending beyond the edge of the slot to guidingly underlie the under surface of the actuating plate.

2. In combination in a crossbar switch, an elongated actuating plate consisting of a single plate-like member pivoted at its ends for rotation about an axis lying near its rear edge, such rotation being between a released position and an actuated position for any selected one of an overlying row of stackups of contact members, select levers for respective ones of said stackups, such levers extending across the plate and comprising a row extending along it, means pivoting each select lever on the plate for rotation about an axis extending through the plate near the rear edge thereof for rotation in the plane of the plate between a non-select position and a select position underlying the associated one of said stackups, said actuating plate having openings therethrough underlying the select levers, and lever-control means extending through said openings into effective engagement with said levers respectively to rotate them as desired between their respective said positions.

.3. In combination in a crossbar switch, an elongated actuating plate consisting of a single platelike member pivoted at its ends for rotation about an axis lying near its rear edge, such rotation being between a released position and an actuated position for any selected one of an overlying row of stackups of contact members, select levers for respective ones of said stackups, such levers extending across the plate and comprising a row extending along it, means pivoting each select lever on the plate for rotation about an axis extending through the plate near the rear edge thereof for rotation in the plane of the plate between a non-select position and a select position underlying the associated one of said stackups, said actuating plate having openings therethrough underlying the select levers, lever-control means extending through said openings into effective engagement with said levers respectively to rotate them as desired between their respective said positions, and guide means attached to the respective levers, the guide means for any eluding end members and longitudinal front and rear members secured together, cross members extending between said front and rear members and supported thereon, a contact bank supported on said cross members, said bank including contact members comprising actuatable stackups disposed in rows extending across the frame, actuating bars and means pivotally supporting them between said longitudinal members in operative relationship with said rows respectively, 10

said supporting means for any said bar including a bearing plate adjustably mounted on one of saidlongitudinal members for movement toward and away from the contact bank to shift one pivot point of any actuating bar with respect to the said contact bank, and means adjustably REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,021,329 Reynolds Nov. 19, 1935 2,309,422 Vigren et a1 Jan. 26, 1943 15 2,476,789 Wiberg et a1 July 19, 1949 2,490,665 Bellamy Dec. 6, 1949 

